Synergistic effect of hybrid carbon nanotube and graphene nanoplatelets reinforcement on processing, microstructure, interfacial stress and mechanical properties of Al2O3 nanocomposites.

Al 2 O 3 , Al 2 O 3 -1 wt% Carbon Nanotube (CNT) and Al 2 O 3 -1 wt% CNT-0.5 wt% Graphene Nanoplatelets (GNP) were consolidated by spark plasma sintering at a temperature of 1500 °C. Spray drying technique was used for uniformly distributing the CNTs and GNPs. Fracture toughness of Al 2 O 3 pellet drastically increased to 168% on addition of CNTs, while substantial improvement of 250% was seen on the addition of both CNTs and GNPs. Interfacial shear stress for Al 2 O 3 -CNT-GNP was found to be 350–1100 MPa. Novel toughening mechanisms such as CNT yarning and CNT embedded graphene was found responsible for the drastic improvement in toughness. [ABSTRACT FROM AUTHOR]